In recent years, the development of digital audio compression technology coupled with the introduction of inexpensive portable audio devices has allowed consumers to carry, literally in their pocket, entire libraries of high quality music to be enjoyed almost anywhere while engaged in almost any activity. These portable devices generally use solid-state memory or miniature computer hard drives to hold hundreds or thousands of megabytes of compressed audio. In order to move music from traditional media (e.g., a Compact Disc™ containing Redbook audio) to the portable device, a consumer generally uses computer software to “rip” the CD and create files containing the compressed audio using an algorithm such as Moving Picture Experts Group (MPEG) Audio Layer 3 (commonly known as MP3). These files may then be copied to the portable device.
An unfortunate side effect of this revolution in audio compression technology has been a substantial increase in copyright infringement and piracy through file swapping over the Internet. Although sharing music with friends and acquaintances via recordable cassette tape and other physical media has been going on for years, high quality audio compression technology combined with one of any number of file swapping software programs can now allow a single consumer to purchase a single copy of an album and almost instantaneously share it with thousands of other individuals worldwide. While some sharing of music among acquaintances can serve to promote a new album or musical act resulting in increased sales, virtually unlimited sharing can drastically erode sales.
A number of potential solutions have been proposed to combat copyright infringement and unlimited copying. Many of these solutions include digital rights management (DRM) schemes which manage virtually every use of the digital content. However, in their present form, these solutions can be difficult and inconvenient to use. Other solutions simply use “anti-ripping” technology to prevent the Redbook audio of a CD from being read by a computer (thus preventing the CD from being ripped) while still allowing it to be read by home stereo equipment. However, this prevents the consumer from making a personal-use copy for use only on the consumer's portable device.
It would be useful to have a solution which prevents or reduces the unlimited file swapping that results in copyright infringement while preserving flexibility and ease of use for the consumer.